Chicken Deaths & Aftermath

[dmeaser]

We had five hens, all one year old, in Los Angeles - two Ameracaunas, a Barred Rock, a Buff Orpington, and a Black Sex Link. One morning, we awoke to discover two dead - one Ameracauna and our Barred Rock. There were no signs of trauma, attack, or any type of predator; also, leading up to the deaths, there were no health symptoms or unusual behavior. These two chickens just seemed to drop dead, both overnight. While we have no idea what caused it, the main suspects seems to be poison or extreme heat.
Since then, the surviving three have seemed very out of it. At first I thought that they might also be sick or effected with whatever killed the other ones, but they have been doing okay. I would almost say they were depressed -- just sort of subdued, low energy, less playful. And now I'm realizing that since the death, only one chicken is laying eggs (the Ameracauna...her eggs are the only blue ones). The other two -- extremely prolific before -- seem to have just stopped laying.
Does anybody have any clue what's going on? Is it possible that their flock-mates' deaths has caused some kind of trauma that's rendered them unable to lay? Or maybe it's connected and perhaps a clue to their deaths?
I have no idea what's going on, and there's no chicken experts around here to ask or help me. I appreciate any responses!

 

[Elizabethwood09]

Have you already checked/treated for mites or lice?

 

[dmeaser]

No, I haven't checked for either.

 

[Elizabethwood09]

That can definitely be a "silent killer" and can lead to the other symptoms you saw. There are definitely those that have more experience on here than me but I know you can also search the threads or Google and there will be a lot of good info on how to treat them.

 

[Elizabethwood09]

@Eggcessive can you help?

 

[Eggcessive]

Sorry for your loss. Can you tell us a little about how your chickens are kept, the daytime temperatures, shade, and the feed? Check your feed right away for any possible mold or color/odor change. Is there any way they could have been poisoned? If you should lose another chicken, refrigerate but don’t freeze the body, and send it to one of the 4 state poultry vets at UCDavis for a necropsy to find a cause of death. It costs $25. Here is contact info:
https://www.cdfa.ca.gov/ahfss/Animal_Health/pdfs/CAHFS_NecropsyFactsheet.pdf

 

[dmeaser]

Thanks for the advice and help. We're in coastal LA, so the temperatures don't get overly hot (though they were very hot this weekend, but the deaths happened last week). We have one of those Omelet coops, which has been a dream, and it also provides good shade; automatic waterer keeps them in fresh water all the time. The feed looked okay, although I do recall changing from an organic feed to the same layer crumble, but a different brand / non-organic. And one more clue: when we discovered them, one hen was just face down dead in the middle of the run, but the other one was in the nest box.